Going All the Whey

It’s not often that all the stars align for a renewable energy project, but that is exactly what happened in Beaver Dam, Wis. At the same time the city of 16,000 needed to expand its wastewater treatment plant (WWTP), Kraft Foods was interested in finding a solution for the whey waste it produced at its Philadelphia Cream Cheese factory in the city.

The Philadelphia Cream Cheese plant in Beaver Dam has been in operation since 1922. Originally the Phenix Cheese Co., it merged with Kraft in 1928 to become the Phenix-Kraft Cheese Co. The facility has been producing the popular food product for the past 90 years. Recently, as sustainability and waste reduction has come into the forefront of American business operations, Kraft Foods began looking for alternatives to disposing of the plant’s whey waste.

Bob Koneck, safety, security and environmental manager at the Kraft Beaver Dam plant, says Kraft has been working to incorporate sustainability into its decisions and actions for many years. “About a decade ago, Kraft began looking for more opportunities to use the whey waste from its cheese plants instead of landspreading the whey. We explored a number of options and producing biogas from the whey became the preferred option.”

Meanwhile, the wastewater treatment plant in Beaver Dam was planning an upgrade to its system as it was running at 140 to 170 percent of its capacity. Don Quarford, director of utilities for the city of Beaver Dam, says, “At the same time we were doing that to expand the plant, Kraft was looking at trying to do something themselves to try to get rid of the whey.”

Building a Partnership
Koneck says Kraft and the city of Beaver Dam have had a longtime working partnership. The plant sends a significant amount of wastewater to the city’s wastewater treatment plant. When Koneck became Kraft’s safety, security and environmental manager in 1999, he began working with Quarford. “It didn’t take long to realize how much the city’s wastewater plant and Kraft’s cream cheese plant impacted each other, so we began sharing information about both our plant operations and what changes we were considering,” say Koneck.

In 2007, Koneck says Kraft began seriously considering use of some type of biogas system while Quarford was working with Jim Smith from Applied Technologies on the city’s wastewater treatment plant expansion plan.

“We were getting ready to review the facility plan, and Don was beginning to look into what the effluent would be like coming from a biogas system into the city’s waste treatment plant. We all thought a biogas system could be a good option for all of us,” says Koneck.

As Kraft was completing a feasibility study that used its current whey flows, Koneck says, Quarford asked if Kraft would be interested to have the Publicly Owned Treatment Works (POTW) install a biogas system to handle the whey.

After meeting with a team at Kraft, Koneck says, “We agreed the scope was based on sound judgment. It would eliminate our landspreading of whey and instead be built into the city’s existing waste treatment facility. And it would be operated by the city’s POTW team, who are the experts in this type of operation.”

Smith of Applied Technologies adds, “The plant knows how to operate and maintain a biogas system. It is one of the advantages of having this partnership. They are the experts at making cream cheese and Don’s expertise is how to generate biogas and use it,” he says of Kraft.

“Jim Smith of Applied Technology, Don Quarford and his team, the mayor, city council, an operating committee, the Wisconsin DNR (Department of Natural Resources) and others worked for one-and-a-half years to finalize the scope, engineering, costs and funding of the 20-year plan with the biogas system,” says Koneck.

Quarford emphasizes the importance of having support from local officials. “City council was 100 percent behind this project and very supportive. They deserve a lot of credit.”

He continues that having support is what enables managers like himself to come up with more innovative ideas. “If you don’t support your managers, they are not going to be aggressive and do these things we do here in Beaver Dam and in other cities.”

Allowing Kraft to meet its sustainability goals helps ensure the company will continue to operate in Beaver Dam, according to Quarford.

Project Scope
The Kraft facility produces 178 million pounds of cheese per year. Whey and other wastewaters are generated from the process. These forms of waste are optimal for producing biogas in anaerobic treatment systems, according to Smith.

The city of Beaver Dam developed a biogas system proposal that Kraft evaluated on technical feasibility, operating cost, energy generation, location and the elimination of landspreading of the whey, recalls Koneck. A letter of intent was presented to the mayor to form a partnership to complete the project and to incorporate the biogas system into the 20-year facility plan.

The anaerobic digestion (AD) system designed to handle Kraft’s cheese waste and produce biogas was built separately from the municipal system at the Beaver Dam WWTP. The pretreatment system consists of dissolved air floatation (DAF) and a 790,000-gallon upflow anaerobic sludge blanket (UASB) reactor. Smith describes the Seimens Paques AD system as a 60-foot high tank. The bottom third of the UASB is made up of a dense concentration of anaerobic organisms, which grab onto the sugars. It takes approximately two days to convert the waste into biogas. The municipal sludge goes through a separate digester. The gas is joined by one common gas system.

Approximately 90 percent of the gas is produced from the USAB system and, according to Smith, it is a “clean” gas that does not require any pretreatment.

This anaerobic treatment system uses wastewater to generate an average of 200 feet per minute of biogas, which is used to power two combined-heat-and-power (CHP) engine generators that produce 800 kilowatts (KW) of electricity. The electricity is sold to a local utility, Alliant Energy. The electricity generated is enough to power 800 homes. In addition, waste heat from the CHP engines is used to heat the buildings and anaerobic treatment processes at the WWTP.

The $20 million project was designed to treat a waste load of a population equivalent to 250,000 people, more than 15 times the population of Beaver Dam. It was funded through the Wisconsin DNR and a $10 million American Recovery and Reinvestment Act grant and a $10 million low-interest Clean Water Fund loan.

Quarford points out that Kraft has no financial commitment to the WTTP upgrade. “They are just a user. We assess and bill based on what they send us and what it costs to treat the whey and make it into biogas.”

Kraft is not the only customer that uses the system. It also takes in corn silage and other acceptable waste.

The AD system came online in spring 2011. According to Quarford, the system is keeping 100,000 gallons per day of whey waste from being spread onto fields and eliminating 300 pounds of phosphorus per day. What is left after the treatment process is pure water. In 2010, the U.S. EPA recognized the project with the PISCES Award. The Performance and Innovation in the SRF (States' Clean Water Revolving Fund) Creating Environmental Success Awards highlight successfully designed projects that further the goal of clean and safe water with exceptional planning, management and financing.

Smith credits the city of Beaver Dam and Kraft for their strong, open lines of communication throughout the project. “Both entities wanted to make this work and worked very diligently from the beginning. We had many meetings with local plant staff here and corporate staff. This is a win-win for everyone. There was a strong line of communication that still continues to this day.”

From Koneck’s perspective, it also has been a great partnership. “I am especially grateful to have worked with Don and Jim on this project. I’ve learned a lot from them and I hope they have from me, too.”

The author is managing editor of Renewable Energy from Waste and can be reached at ksmith@gie.net.